Furnace for the manufacture of steel.



No. 771,872. I PATENTED OUT. 11, 1904.

G. GIN.

FURNACE FOR THE MANUFACTURE OF STEEL.

APPLICATION FILED JUNE so, 1903.

N0 MODEL. 2 SHEETS-SHEET 1.

PA'TENTED OUT. 11, 1904.

. G. GIN. FURNACE FOR THE MANUFACTURE OF STEEL.

APPLICATION FILED JUNE 30, 1903.

2 SHEETS-SHEET 2.

N0 MODEL.

Wit/2 asses j/mic Bmwqiswm UNITED STATES Patented October 11, 1904.

PATENT OFFICE.

GUSTAVE GIN, OF PARIS, FRANCE.

SPECIFICATION forming part of Letters Patent No. 771,872, dated October 11, 1904;.

Application filed 1116 30, 1903- To all whom it may concern:

Be it known that I, GUsrAvE GIN, acitizen of the French Republic, residing in Paris, in the Republic of France, have invented a new and useful Improvement in Furnaces for the Manufacture of Steel, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, in which- Figure 1 is a longitudinal section of the furnace. Fig. 2 is a plan view. Fig. 3 is a crosssection. Fig. i is an enlarged section of one of the terminals.

Heretofore in the devices which have been proposed for the production of electrothermic reactions in a melted cast-iron bath great difficulties have been encountered in utilizing the energy of the electric current in a bath the resistance of which is but little over one hundred microhms centimeters. Generally the transformation of electric energy into heat took place largely, if not entirely, in thelayer of slag floating upon the metallic bath, the resistance of this slag being considerably higher than that of the metal. Moreover, the carbon electrodes used in connection with these devices are an obstacle to decarburization, for the reduction of the constituents of the slag is eflected more by the carbon of the electrodes than by the carbon which is in combination with or dissolved in the bath. It has also been proposed to construct furnaces in which the current which traverses the bath is generated by induction without the assistance of electrodes; but it must be pointed out that in apparatuses of this kind there isa considerable magnetic dispersion, which does not allow the proper utilization of electric energy.

My furnace is constructed in such a manner as to avoid the disadvantages I have pointed out. The resistance of the slag is not a necessary element of its operation, and the objectionable use of carbon electrodes is done away with.

The working hearth of my furnace is a long channel of moderate section, which is filled with fused metal and the extremities of which are connected with bowl-shaped terminals made of hollow blocks of soft steel cooled by means of internal water circulation. By caus- Serial No. 163,689. (No model.)

ing a current of sufiicient intensity to pass from one terminal to the other through the melted metal a certain quantity of heat is disengaged which is suificient to maintain the mass in fusion and raise it to the most favorable temperature for the production of purifying reactions. The blocks forming the terminals have a large cross-section, so that the passage of the current does not find resistance enough to develop much heat, the temperature being also limited by the internal circulation of cold water. In order to give a suitable form to the crucible, the channel which forms the working hearth and extends from pole to pole is preferably made in a sinuous path of several parallel channels communicating with each other. In this manner the stream of metal is comparable to the carbon filament in an incandescent lamp.

In practice I have adopted the construction I am about to describe, which will explain the working of my furnace.

The purifying apparatus consists mainly of a movable truck 1, running on rails. On this truck a heartlf 2, of refractory material, is placed, and the sinuous channel 3, which contains the fused metal, is provided in the hearth, care being taken that the two extremities of this channel reach the terminals 4r, made of bowl-shaped hollow blocks of steel, one side being open in continuation of the'channel 3. The terminalsgllare cooled by an internal water circulation, which penetrates into the cavity 5 by means of a strong rubber tube 6, connected to the water-supply, the escape being through an orifice 7, which is also supplied with a rubber tube connected with the wastepipe. The terminalsareinsulated at 15. (See Fig. I.) An oven-like structure 8, having a roof 9 made of refractory material is provided, and at the beginning of the operation the truck and hearth are made to penetrate into the oven, the hearth being directly under the roof, so as to prevent the loss of heat by radiation. WVhen the hearth is in place, electric connections are made atlglg and the liquid iron is poured through funnels 11, going through the roof.

Any of the known processes for making steel can be used. The pig-and-scrap process can easily be practiced by adding to the melted pig-iron the proportion of scrap which after being dissolved into the bath Will give the right amount of carbon in the finished product. In this case the operation will last no longer than the complete fusion of the added scrap. The pig-and-ore process can also be used, the addition of ore being made, just as in any other furnace, in successive additions until the carbon is practically eliminated and tests can be taken. It must be remarked that the carbon of the pig will in my furnace be eliminated more rapidly than in the Siemens furnace on account of the higher temperature obtained.

The hearth may be acid or basic, and if basic the operation will be conducted as usual, additions of basic material being provided for the elimination of phosphorus and sulfur.

Slags can be raked off at the front of the furnace. The metal may be tapped at the front of the furnace through orifices 12, provided for this purpose.

It will be noticed that the oxidation of the impurities of the cast-iron, and mainly the carbon, takes place without the direct action of atmospheric oxygen. In this manner the internal oxidation of the metal bathis avoided, and the proportion of deoxidizing reagents introduced at the end of the operation is considerably decreased. Finally, all heat developed being localized in the metallic conductor, it will be possible to obtain temperatures which could be reached in the Siemens furnace only on condition of burning the roof and ports as well as the metal placed on the hearth.

What I claim is- 1. In a furnace for the manufacture of steel, a furnace structure, and a hearth inclosed by and movable relatively to said furnace structure, the hearth having two non-carbon electrodes to connect it with a source of electrical energy and having an open channel in which the iron is placed to be treated while at rest, the electrodes being the terminal points of the channel.

2. In afurnace for the manufacture of steel,

a furnace structure, and a hearth inclosed by and movable relatively to said furnace structure, the hearth having two non-carbon electrodes to connect it with a source of electrical energy and having a circuitous open channel in which the iron is placed to be treated while at rest, the electrod es being the terminal points of the channel.

In testimony whereof lhave signed my name in the presence of two subscribing witnesses.

GUSTAVE GIN. [L. s]

WVitnesses:

HELITALO, J. ALLISON BOWEN. 

